Troubled San Francisco homicide detective Valerie Hart is planning a rare weekend away from the job when she gets the call. A body has been found. A woman, brutally murdered. And the cryptic note left by the body is addressed to Valerie.

The victim is unknown to her, but as Valerie analyses the scene, the clues begin to point in a deeply disturbing direction: to a maximum security prison where a woman called Katherine Glass is awaiting execution for a series of gruesome killings. And Valerie was the cop who put her there.

The last thing Valerie wants to do is re-enter Katherine's twisted world, but when a second body is discovered, with another puzzling clue, she realises she has no choice. Katherine Glass holds the key to the killings, and Valerie needs to find out what she knows before the murders come even closer to home.

Even if it means playing a deadly game where once again, the psychopathic killer holds all the cards.

Pachinko by Min Jin Lee

Pachinko follows one Korean family through the generations, beginning in early 1900s Korea with Sunja, the prized daughter of a poor yet proud family, whose unplanned pregnancy threatens to shame them all. Deserted by her lover, Sunja is saved when a young tubercular minister offers to marry and bring her to Japan.

So begins a sweeping saga of an exceptional family in exile from its homeland and caught in the indifferent arc of history. Through desperate struggles and hard-won triumphs, its members are bound together by deep roots as they face enduring questions of faith, family, and identity.

The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars by Dava Sobel

In the mid-nineteenth century, the Harvard College Observatory began employing women as calculators, or “human computers,” to interpret the observations their male counterparts made via telescope each night.

At the outset this group included the wives, sisters, and daughters of the resident astronomers, but soon the female corps included graduates of the new women's colleges—Vassar, Wellesley, and Smith. As photography transformed the practice of astronomy, the ladies turned from computation to studying the stars captured nightly on glass photographic plates.

The “glass universe” of half a million plates that Harvard amassed over the ensuing decades—through the generous support of Mrs. Anna Palmer Draper, the widow of a pioneer in stellar photography—enabled the women to make extraordinary discoveries that attracted worldwide acclaim.

They helped discern what stars were made of, divided the stars into meaningful categories for further research, and found a way to measure distances across space by starlight.

Their ranks included Williamina Fleming, a Scottish woman originally hired as a maid who went on to identify ten novae and more than three hundred variable stars; Annie Jump Cannon, who designed a stellar classification system that was adopted by astronomers the world over and is still in use; and Dr. Cecilia Helena Payne, who in 1956 became the first ever woman professor of astronomy at Harvard—and Harvard’s first female department chair.